1/2(x+y)^2 和（1/2x+1/2y）^2 的计算结果一样吗?

计算 (x+2y)(x-2y)+(x+1)和x(x-1)-(x-31)(x+31) (x-2y)(x+y)-2x(-2x-3y)+6x(-x-y),其中x=-1,y=2要讲解和答题 计算x²-x/x²×x/1-x和x²-4y²/x²+2xy+y²÷x+2y/x²+xy x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 方程组2x-(x+y)=-1和x+4(x+y)=22 (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 (x+2y-5)^2和（x-2y-1)(x+2y-1)的结果 2x+4y=3 -3x-2y=1 ..求x和y 2x+y=1,25x+2y=-40,求x和y? 解方程组,(x+y)^2-3(x+y)=0和x-y=1 已知X和Y满足3X+4Y=2,X-Y-1/7 方程x(x*x+y*y-1)=0和x*x-(x*x+y*y-1)^2=0表示的图形是? (2x-2y)/3-(x-y)=-1和6(x+y)-4(2x-y)=16 解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1kkkkkkkk 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) 若x.y满足x+=4和x-y=2,求xy分之2x-y+1除以-x分之y+y分之x的值 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x²